Florentín, J. E., Nuñez Florentin, M., & Barea Pastore, J. F. (2019).

Four highland species of Galianthe (Rubiaceae: Spermacoceae) with restricted distribution in South America: conservation assessment and complete descriptions

. Phytotaxa, 402(6), 265–280. https://doi.org/10.11646/phytotaxa.402.6.1